Germany’s Secret Underwater World — Full Documentary

[00:00:00] Speaker 1: Germany's rivers, streams and lakes conceal an underwater world that few have seen. It's one of nature's best-kept secrets. Hidden beneath the surface are some little known and bizarre animals. From swarms of microscopic creatures to exotic curiosities and some of the largest freshwater giants on this planet. This is a journey unlike any other, from the snow-clad peaks of the Alps to the tidal waters of the North Sea, offering a rare glimpse into a colourful and mysterious underwater world. Underwater world. The journey begins in the Alps. [00:01:21] Speaker ?: The journey begins in the Alps, Europe's highest mountain range. [00:01:33] Speaker 1: In the Bechtersgaden National Park, the sun's warming rays melt away the layers of snow to reveal the first signs of spring. Underwater water slowly and silently carves away at the ice, forming a large underground cave. Drop by drop, the glacial dome releases its waters into the icy stream below, forming the Iceback River. Every cubic meter of snow yields more than two bathtubs full of water. It's a huge reservoir of fresh water on the mountain slopes. Each spring, torrents of melt water pour down the mountainsides, producing some of the highest waterfalls in Germany, including the Röhrtbachfalls, with a drop of 470 meters. At the base of the fall, the water continues its journey underground, seeping into the porous limestone rocks. The Iceback River shares a similar fate. It disappears into the ground just before reaching the Koenigse. This deep fjord-like lake is renowned for its clear blue waters, which attract many visitors. The steep walls of the lake seem to continue endlessly downwards. The Koenigse is one of Germany's deepest lakes. At the shallow end of the lake, the cold waters of the Iceback River surface again. The crystal clear waters are poor in nutrients, creating a unique habitat. A shoal of small fish seek shelter among the sunken trees at the water's edge. They make an easy meal for predators. But the large northern pike is after much bigger prey. The ferocious water wolf is the most powerful predator in the lake, and even other hunters, such as perch, keep out of the way. With a length of up to a metre and a half, the size of a twelve-year-old boy, it dwarfs all others in the lake, and has no natural enemies other than man. Small fish and invertebrates find shelter from predators amongst the water plants, that grow in the shallow and sunlit parts of the lake. The pike is an ambush predator, which has a trick up its sleeve. Its colours and markings match the surroundings, so that it's well camouflaged. Some have yellow golden stripes and spots, while others are a silvery blue. At the beginning of May, the pike gather in their favourite spawning sites, ready for the breeding season. The males arrive a few days before the females. She is the larger of the two, and he needs to keep up with her, staying close by her side. This mating ritual can last several days. The smaller male may well be wary of his large partner. Pike are known to resort to cannibalism when food is scarce, and will not shy away from eating their counterparts. But nature has found a solution to this problem. Females do not feed during the breeding season, ensuring that their partners and future offspring are safe. are safe. The social life of frogs and toads is a less precarious affair. They do not partake in cannibalism. The beginning of the breeding season is an excuse for one gigantic party. While intentions may be amorous, things can sometimes get out of hand. In the ensuing mating frenzy, a group of writhing males may risk drowning the object of their desire. After two or three days of frenetic activity, it's all over. After two or three days of frenetic activity, it's all over. [00:08:13] Speaker ?: After two or three days of frenetic activity, it's all over. After two or three days of frenetic activity, it's all over. After two or three days of frenetic activity, it's all over. After two or three days of frenetic activity, it's all over. After two or three days of frenetic activity, it's all over. After two or three days of frenetic activity, it's all over. After two or three days of frenetic activity, it's all over. After two or three days of frenetic activity, it's all over. After two or three days of frenetic activity, it's all over. [00:08:25] Speaker 1: After two or three days of frenetic activity, it's all over. It's all over. A storm is brewing above the newly laid spawn. A heavy downpour quickly raises the water levels in the Königsee. Within a few hours, the streams are wild and unruly. Now there is only one way out of the lake, through the Königsee Weir. This man-made barrier helps control the flow of the river. Countless brooks and streams, fed by glacial water and rain, carve their way down the mountainsides. The water starts as a trickle, soon becomes a gushing cascade, gathering in force both above and below the ground. The power of the water shapes the landscape, wearing down rocks and entire mountains. The river Rhine is one such stream, born high up in the Alps. Now it winds its way towards the plains, until it empties its waters into Lake Konstanz, one of Germany's biggest lakes, depositing huge amounts of sediments carried down from the mountains. The cold, turbid water quickly sinks to the bottom. Millions of tons of sediment are poured into the lake each year. The milky curtain gives way to clearer waters, and a dazzling array of underwater creatures. A stickleback guards its nest, and fans the eggs to ensure they have a steady supply of oxygen. A pair of pumpkin seed fish, an invasive species from North America, are immersed in their courtship dance. In the deeper water of the lake, a hungry pike is on the prowl. Once it has identified a target, there is little chance of escape. [00:11:54] Speaker ?: Once it has detected, there is little chance of escape. There is little chance of escape. Once it has detected, there is little chance of escape. The victim's partner is unlikely to fare much better. The victim's partner is unlikely to fare much better. The victim's partner is unlikely to fare much better. The victim's partner is unlikely to fare much better. The victim's partner is unlikely to fare much better. the victim's partner is unlikely to fare much better. The victim's partner is unlikely to fare much better. The victim's partner is unlikely to fare much better. The victim's partner is unlikely to fare much better. The victim's partner is unlikely to fare much better. The victim's partner is unlikely to fare much better. The dense underwater forests are home to a more secretive hunter. But the victim's partner is unlikely to fare much better. The victim's partner is unlikely to fare much better. The victim's partner is unlikely to fare much better. [00:12:13] Speaker 1: The victim's partner is unlikely to fare much better. [00:12:20] Speaker ?: The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. [00:12:37] Speaker 1: But if the victim's partner is unlikely to do much better, the victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. [00:12:42] Speaker ?: The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. [00:12:45] Speaker 1: The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. [00:12:51] Speaker ?: The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. [00:12:53] Speaker 1: The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. [00:13:01] Speaker ?: The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. [00:13:08] Speaker 1: The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is unlikely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. [00:13:16] Speaker ?: The victim's partner is likely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. [00:13:23] Speaker 1: The victim's partner is likely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. [00:13:29] Speaker ?: The victim's partner is likely to do much better. [00:13:30] Speaker 1: The victim's partner is likely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. [00:13:37] Speaker ?: The victim's partner is likely to do much better. [00:13:38] Speaker 1: The victim's partner is likely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. The victim's partner is likely to do much better. Lake Constance is over 250 meters deep, formed by glaciers during the Ice Age. The little light that penetrates beyond a depth of 30 meters is not sufficient to sustain plant growth. Creatures that live here need to be highly specialized. Zebra mussels were accidentally introduced in the 1960s and have rapidly multiplied. Today, huge carpets of mussels cover the rock face, filtering tiny particles of food from the water. They have become an important source of food for many diving ducks. The burbot is the only member of the cod family that lives in fresh water. It also lives in the cold darkness at the bottom of the lake. The lake floor is home to a community of highly specialized creatures. They scavenge on the dead remains of plants and animals that have sunk to the bottom. Fresh water crabs search the lake bed for carcasses. They are nature's recyclers and together with tiny worms and bacteria ensure that nothing is wasted. Lake Constance is also a massive ship graveyard. Numerous old wrecks, such as the paddle steamer Jura, lie in the dark, waiting for the sediments drifting down from above to bury them completely. Lake Constance has long been an important shipping route for Germany, Austria and Switzerland. and most of the shoreline is well developed. Over three and a half million people live along its shores. The large human population makes life increasingly difficult for the lake's wildlife. And each year, another six million tourists and countless day visitors descend on the area. The lake is struggling to survive under the onslaught. Lake Constance has long attracted human settlers to its shores, and the evidence can still be seen under the surface today. The first settlements date back to 4,000 years BC. These early pioneers built their houses on stilts in the water. The water offered them safety from enemies and wild animals. Today these ancient dwellings are a world heritage site. The sunlit edges of the lake are rich in wildlife. [00:18:43] Speaker 2: The shallow waters are the perfect nursery grounds for small fish. [00:18:59] Speaker 1: It's easy pickings for the grey heron. [00:19:13] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. In the water is up to the shoreline. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:19:26] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:19:30] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:19:39] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:19:53] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:20:20] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:20:26] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:20:41] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:20:56] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:21:23] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:21:31] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:21:39] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:21:50] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:21:57] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:22:06] Speaker ?: It's easy to keep on living. It's easy to keep on living. [00:22:08] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:22:20] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:22:23] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:22:30] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:22:39] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:22:50] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:23:02] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:23:23] Speaker ?: It's easy to keep on living. It's easy to keep on living. [00:23:25] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:23:31] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:23:34] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:23:51] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:23:59] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:24:04] Speaker ?: It's easy to keep on living. It's easy to keep on living. [00:24:06] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:24:09] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:24:20] Speaker 1: It's easy to keep on living. [00:24:21] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:24:26] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:24:29] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:24:33] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:24:37] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:25:02] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:25:10] Speaker ?: It's easy to keep on living. It's easy to keep on living. [00:25:20] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:25:27] Speaker ?: It's easy to keep on living. [00:25:28] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:25:34] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:25:38] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:25:50] Speaker ?: It's easy to keep on living. [00:25:51] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:25:56] Speaker ?: It's easy to keep on living. It's easy to keep on living. [00:25:58] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:26:02] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:26:21] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:26:28] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:26:31] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:26:40] Speaker ?: It's easy to keep on living. It's easy to keep on living. [00:26:50] Speaker 1: It's easy to keep on living. [00:26:51] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:26:54] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:27:01] Speaker ?: It's easy to keep on living. It's easy to keep on living. [00:27:03] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:27:07] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:27:38] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:27:50] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:27:59] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:28:02] Speaker 2: It's easy to keep on living. [00:28:03] Speaker 1: It's easy to keep on living. It's easy to keep on living. [00:28:05] Speaker 2: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:28:08] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:28:20] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:28:29] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:28:38] Speaker ?: It's easy to keep on living. [00:28:39] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:28:50] Speaker ?: It's easy to keep on living. [00:28:51] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:28:57] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:29:04] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:29:09] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:29:20] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:29:23] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:29:39] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:29:50] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:30:04] Speaker 1: It's easy to keep on living. It's easy to keep on living. [00:30:06] Speaker ?: It's easy to keep on living. [00:30:07] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:30:23] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:30:41] Speaker 1: It's easy to keep on living. It's easy to keep on living. [00:30:50] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:31:02] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:31:07] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:31:20] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:31:24] Speaker ?: It's easy to keep on living. It's easy to keep on living. [00:31:26] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:31:29] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:31:35] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:31:38] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:31:50] Speaker 2: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:31:54] Speaker ?: It's easy to keep on living. It's easy to keep on living. [00:31:56] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:31:59] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:32:20] Speaker 1: It's easy to keep on living. [00:32:21] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:32:30] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:32:33] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:32:39] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:32:55] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:33:03] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:33:20] Speaker ?: It's easy to keep on living. [00:33:21] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:33:30] Speaker ?: It's easy to keep on living. It's easy to keep on living. [00:33:32] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:33:40] Speaker ?: It's easy to keep on living. It's easy to keep on living. [00:33:50] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:33:56] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:34:11] Speaker 1: It's easy to keep on living. [00:34:20] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:34:27] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:34:31] Speaker ?: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. [00:34:39] Speaker 1: It's easy to keep on living. It's easy to keep on living. It's easy to keep on living. Diving here is tricky and dangerous. And much of the vast labyrinth is still unexplored. Only the most experienced divers are allowed down here, into this unknown world. The deeper they penetrate, the more they discover. Enormous caves the size of cathedrals, and the most spectacular natural sculptures. It's a majestic fairyland of stalactites and stalagmites, stone pillars and stone curtains. It's a challenge navigating away through the rocky maze, and not without its hazards. For the moment, they face the narrowest of rock crevices. The next, a descent into a deep sinkhole. So far, only 10 kilometers of the cave system has been explored. But it's thought to be several dozen kilometers long. Cave exploration is as much of an adventure as a science. Part of the aim is to map the underground terrain, and get a better understanding of the geology. The hard work and persistence, finally pays off. The hard work and persistence, finally pays off. The hard work and persistence, finally pays off. Chemical analyses may provide clues as to the source of the water, and the route it has covered. Of course, it has covered. [00:37:52] Speaker ?: It is covered. It is covered. [00:38:20] Speaker 1: At the northern rim of the Swabian Alps, the water flows directly from the river Neckar into the Rhine. The upper Rhine is more of a canal than a river, having been straightened in the 19th century. It was once up to three kilometers wide in parts, winding its way through the swampy floodplains. Until a few decades ago, the water was highly polluted. In recent years, this has changed, bringing back many of the fish that had long disappeared. along the small side-arms of the river, swampy forests that once covered the floodplain are still preserved today. It's Germany's Amazon, rich in wildlife. And it's the only one way through the river. [00:39:23] Speaker ?: It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. [00:39:35] Speaker 1: It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. [00:39:40] Speaker ?: It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. [00:39:46] Speaker 1: It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. [00:39:53] Speaker ?: It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. [00:40:00] Speaker 1: It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. [00:40:08] Speaker ?: It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. [00:40:12] Speaker 1: It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. [00:40:18] Speaker ?: It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. It's the only one way through the river. [00:40:23] Speaker 1: The near tropical conditions and warm sunshine are maybe not that different to the Everglades in Florida. It's an idyllic scene, completed by the display of yellow flowers of the bladderwort. But beneath the surface, the story is more sinister. The bladderwort is a carnivorous hunter. The small bladders are in fact deadly traps. Inside, there is a partial vacuum. The slightest touch to one of the trigger hairs, and the trapdoor flies open, sucking in passing prey. It all takes just a split second. The flooded forests are also home to a larger predator: the European otter. With its long, streamlined body, it's perfectly adapted to a life in water. The thick, waterproof fur keeps them dry and warm underwater, so they can play for hours on end. For centuries, otters were persecuted for their fur and disappeared from many parts of Germany. Today, they are protected, and populations are slowly recovering again. It's midsummer. The pike hatchlings are now big enough to hunt for prey. But small fish only need small meals: fish-borne, water fleas, and small insects. They are still only 4cm long, but already bold enough to tackle other fish. But this one has bitten off more than it can chew. Other small hunters are hiding in the vegetation. Tiny, soft-bodied polyps, called hydra, stretch out their thin arms in search of prey. Their tentacles are lined with highly specialized stinging cells that will fire poisonous threads into their victim. A dense cloud of fresh water shrimp. They've invaded Western Europe from the Black Sea, and are spreading rapidly through Germany. Divers have reported seeing colossal swarms of millions of animals. A jellyfish, another invasive species. Originally from Southeast Asia, it has successfully managed to spread around the world. It's the only fresh water jellyfish to be found in Europe. This exotic invader feeds mainly on water fleas and other small invertebrates. So far, it seems to be causing little damage to its new home. The turtles calmly watch the activities of the busy otters. Newcomers and old residents live peacefully side by side here. It would seem that not all new arrivals are harmful to the environment. Some simply make our natural world a little more colourful. It's autumn and there's change in the air. The colourful autumn leaves float down to the surface before sinking to the bottom of the stream. It's an annual cycle of life and death that is played out both above and below water. Purple sulfur bacteria thrive in the stagnant water and decompose the dead leaves and vegetation. It's a surreal landscape. The purple globes floating within a virtual galaxy. Each autumn, the bacteria form shroud-like blooms. But by the coming spring, they've disappeared again. This underwater wall of fog is also formed by bacteria. It's a sign that winter is on its way. The eerie calls of the common crane echo through the valley, as they gather to begin their long migration south. The otter's thick fur also protects it against the cold winter. All it needs at this time of year is some open water where it can hunt for fish. A thick layer of ice has formed, sealing off the shallow pools and lakes. [00:48:01] Speaker ?: A thick layer of ice has formed, sealing off the shallow pools and lakes. A thick layer of ice has formed, sealing off the shallow pools and lakes. [00:48:12] Speaker 1: The cold temperatures have driven most creatures into hiding. The fish seek out a sheltered spot near the bottom, and sit out the winter in a torpor. They slow down their metabolism and breathing to save energy, and wait for spring. Once temperatures rise again, the water, now locked in ice, will be freed once more, and can continue its journey towards the sea. [00:49:08] Speaker ?: The sea is the most important part of the sea. The sea is the most important part of the sea. The sea is the most important part of the sea. The sea is the most important part of the sea. The sea is the most important part of the sea. The sea is the most important part of the sea. The sea is the most important part of the sea. The sea is the most important part of the sea. The sea is the most important part of the sea. The sea is the most important part of the sea. The sea is the most important part of the sea. The sea is the most important part of the sea. The sea is the most important part of the sea. The sea is the most important part of the sea. The sea is the most important part of the sea. The sea is the most important part of the sea. The sea is the most important part of the sea.